Lens driving device

ABSTRACT

The present invention is a lens driving device comprising first driving coils  30   a  which relatively moves a lens holder  40  against a base part  10  along X axis perpendicular to an optical axis of a lens  100,  and second driving coils  30   b  which relatively moves a lens holder  40  against a base part  10  along Y axis perpendicular to an optical axis. At the base part  10,  an opening part  12  is formed where a part of the lens  100  is to be inserted in a movable manner along the driving plane. The oblique diameter Dxy 1  and Dxy 2  of the opening part  12  along the oblique direction positioned at the middle of X axis and Y axis, is larger than the first inner diameter Dx along X axis direction of the opening part  12,  and also larger than the second inner diameter Dy along Y axis direction of the opening part  12.  At the base part  10,  the cylinder shape projection part  14  is formed along the periphery of the opening part  12.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lens driving device suitably used forinstance as a camera module of a mobile phone or so.

2. Description of the Related Art

In the lens driving device suitably used for instance as the cameramodule of the mobile phone or so, the device has been developed whichcarries out the blur correction by moving the blur correction movablepart including a lens holder holding the lens in the perpendiculardirection along the optical axis (for example refer to following patentdocument 1). In order to carry out the blur correction by moving theblur correction movable part in the perpendicular direction along theoptical axis, a part of a first driving part having a first drivingaxis, and a part of a second driving part having a second driving axisare provided to a base part.

At the base part, an opening part is formed where at least part of thelens held by the lens holder is inserted. For the conventional devices,the opening part of the base part is formed in a circular shape to matchwith an outer shape of the lens. Also, in order to move the lens withrespect the base part in the perpendicular direction against the opticalaxis, the inner diameter of the opening part is made larger than theouter diameter of the lens inserted to the opening part.

The size of the base part is preferably as small as possible in order toachieve a compact device. Therefore, if the inner diameter of theopening part which is formed at the base part is too large, the distancebetween the outer sides of the base part and the opening part isshortened, thereby the space to place the driving part on the base partwill be lost. Thus, the inner diameter of the opening part is made tohave minimum size necessary in accordance with the outer diameter of thelens.

Thus, it has been thought to design the inner diameter of the openingpart of the base part so to secure the maximum moving amount along firstdriving axis direction of the lens, or to secure the maximum movingamount along the second driving axis direction of the lens. By designingas such, in case the lens moves only to the first driving axis directionor moves only to the second driving axis direction, there is no risk oflens colliding to the periphery of the opening part.

However, the lens does not necessarily move only along the first drivingaxis direction or only along the second driving axis direction, but forexample, it also moves along the oblique direction positioned in middleof the first driving axis and the second driving axis. In the obliquedirection, the lens moves along the moving vector corresponding to thesum of the moving vector along the first driving axis and the movingvector along the second driving axis.

Therefore, the moving amount of the lens in the oblique direction islonger by √2 times or so (about 1.44 times) at maximum compared to themoving amount along the first driving axis and the second driving axis;and in the worst case scenario, the lens might collide to the peripheryof the opening part of the base part. When the lens collides against theperiphery of the opening part of the base part, the lens might bedamaged and also there may be a problem such as declined quality of blurcorrection or so due to the impact of the collision.

In order to avoid such problems, the opening part of the inner diameterwhich is unnecessarily larger compared to the diameter of the lens isformed at the base part. Therefore, it is difficult to make the size ofthe base part compact; hence as a result, it was unable to make thedevice compact.

[Patent document 1] JP Patent Application Laid Open No. 2011-65140

SUMMARY OF THE INVENTION

The present invention has been achieved in view of such situation, andthe first object is to provide the lens driving device capable of makingthe device compact, and also to reduce the risk of the lens collidingagainst the periphery of the opening part of the base part. The secondobject of the present invention is to provide the lens driving devicecapable of preventing the particles from flowing into the opening partof the base.

In order to achieve said first object, the lens driving device accordingto the first aspect of the present invention comprises,

a first driving part allowing a lens part including at least one lens torelatively move against a base part along a first driving axis crossingwith an optical axis of said lens,

a second driving part allowing said lens part to relatively move againstsaid base along a second driving axis crossing with said optical axis ofthe lens and with said first driving axis, wherein

an opening part is formed at said base part to which a part of said lensis inserted in a movable manner along a driving plane including saidfirst driving axis and said second driving axis, and

an oblique internal diameter of said opening part along an obliquedirection positioned in the middle of said first driving axis and saidsecond driving axis is larger than a first internal diameter of saidopening part along a direction of said first driving axis, and alsolarger than a second internal diameter of said opening part along adirection of said second driving axis.

The lens driving device according to the first aspect of the presentinvention has the oblique inner diameter of the opening part along theoblique direction positioned between the first driving axis and thesecond driving axis larger than the first inner diameter along the firstdriving axis direction of the opening part; and also larger than thesecond inner diameter along the second driving axis direction of theopening part. By taking such constitution, not only in case the lensmoves along the first driving axis direction or the second driving axisdirection, but also in case the lens moves along the oblique directionin the middle thereof, the risk of the lens colliding to the peripheryof the opening part can be removed.

Furthermore, as for the lens driving device according to the firstaspect of the present invention, the opening part formed at the basepart does not form a perfect circle, but has an atypical shape whereinthe inner diameter along the oblique direction positioned in the middleof the first driving axis direction and the second driving axisdirection is larger than the inner diameter along the firs driving axisdirection or the second driving axis direction. Therefore, compared tothe opening part of perfect circle which was determined based on themaximum moving amount along the oblique direction, the size of the basepart can be made small, and this contributes to achieve the compactdevice.

Alternatively, if the size of the base part is the same as the size ofthe conventional base part, compared to the opening part of perfectcircle which was determined based on the maximum moving amount along theoblique direction, in the present invention, the width of the base partalong the first driving axis and the second driving axis can be madelarger. Therefore, the number of windings of the coil which constitutesa part of the first driving part and the second driving part can beincreased, hence the driving force is enhanced, and the accuracy of theblur correction is improved.

Preferably, said first driving part includes a pair of first drivingcoils positioned at both sides along said first driving axis directionwhile placing said opening part therebetween, and

a pair of said first driving coils are placed parallel along opposingtwo sides of said base part.

By taking such constitution, the driving force along the first drivingdirection is enhanced, and the accuracy of the blur correction isimproved.

Preferably, said second driving part includes a pair of second drivingcoils positioned at both sides along said second driving axis whileplacing said opening part therebetween, and

a pair of said second driving coils are placed parallel along opposingtwo sides of said base part.

By taking such constitution, the driving force along the second drivingdirection is enhanced, and the accuracy of the blur correction isimproved.

Preferably, said lens part is held at a flame in a movable manner in theoptical axis direction, and

said flame is held in a movable manner along said driving plane againstsaid base part using plurality of suspension wires.

By taking such constitution, the lens part can move freely along thedriving plane against the base part.

Preferably, said flame has a square ring shape as a whole and placedinside a case of square cylinder shape fixed to said base, and

said oblique direction roughly matches to a diagonal line direction ofsaid square ring shape.

By taking such constitution, it enables to efficiently place a part offirst driving part and a part of the second driving part on the basepart, thus the size of the base part can be made smaller and the devicecan be made compact easily.

Preferably, a cylinder shape projection part is formed at said base partalong a periphery of the opening part, and

at least part of said first driving part and said second driving partare placed around said cylinder shape projection part.

By taking such constitution, it can effectively prevent the lens fromcolliding against at least a part of the first driving part and thesecond driving part (the driving coil) placed around the cylinder shapeprojection part. Also, by having the cylinder shape projection part, thedust present at the surface of the base part becomes difficult to enterinside the opening part. At the inside of the opening part, the lens isinserted, and at the positioned spaced apart along the optical axisdirection of the lens, the image sensor or so is placed. When the dustor so attaches to the image sensor element, the quality of the images tobe taken may decline, thus preferably the dust does not enter inside theopening part.

In order to achieve the above mentioned second object, the lens drivingdevice according to the second aspect of the present invention comprisesa movable part having a lens holder holding a lens and a driving magnetfor driving said lens in optical axis perpendicular direction,

a fixing part having a driving coil placed to face against said drivingmagnet to drive said lens in said optical axis perpendicular direction,and a base part formed with a base opening part to allow an incidentlight on said lens to pass through and the base part is also providedwith said driving coil, and

a supporting part connecting said movable part to said fixing part inrelative movable manner, and supporting said movable part to said fixingpart, wherein

a cylinder projection part which projects out along the optical axisdirection of said lens towards said movable part is formed along aperiphery of said base opening part at said base part,

a projection end of said cylinder shape projection part is positioned atfront side along the optical axis direction of said lens than a coilmounting plane where said driving coil is mounted in said base part, and

a coil front end of said driving coil is positioned at front side alongsaid optical axis direction than said projection end.

In the lens driving device according to the second aspect of the presentinvention, the cylinder projection part is formed along the periphery ofthe base opening part; hence in case the particles are generated in thelens driving device, the particles can be stopped by the cylinderprojection part. Therefore, the particles can be prevented from flowingin from the base opening part to the image sensor side which is at therear side (the opposite of the front side along the optical axis). Notethat, the front side along the optical axis refers to the side closer tothe movable part along the optical axis, and matches with the enteringside when the light passes through (the image object side); and the rearside refers to the side away from the movable part along the opticalaxis, and matches with the exiting side of light.

Further, the projection end of the cylinder shape projection part ispositioned at the front side than the coil mounting plane, and it isalso positioned at rear side than the coil front end of the drivingcoil. Therefore, even in case the movable part and the fixing partcontacts against each other due to the impact or so from the outside,since the coil is placed closer to the movable part than the cylindershape projection part, the cylinder shape projection part can beprevented from directly contacting with the movable part. Therefore,even if the movable part and the fixing part collides against eachother, the particles generated by the collision can be prevented fromflowing into the image sensor side via the base opening part, since theposition of the collision will be further towards the outercircumference side than the cylinder shape projection part.

Also, for example, a predetermined space may be formed between an outerperipheral side plane of said cylinder shape projection part and saiddriving coil.

Even in case the particles at the front plane of the driving coil movestowards the base opening part, these particles will be trapped in suchspace, hence the particles can be effectively prevented from flowinginto the image sensor side via the base opening part.

Also, for example, a wire connecting to said driving coil may be placedin said space.

By placing the wire connecting to the driving coil at the space, thewire distance of the driving coil can be shortened, and also the spacefor placing other members in the base part can be made wider.

Also, for example, said outer peripheral side plane of said cylinderprojection part may comprise a projection part flat plane part extendingparallel to a flat plane including said optical axis, and

said projection part flat plane part may face against, by placing thespace in between, a coil flat plane part which is part of the outercircumference side plane of said driving coil and extending parallel tothe flat plane including said optical axis.

By taking such constitution, the particles tend to be easily trapped inthe space formed between the outer peripheral side plane of the cylindershape projection part and the side plane of the driving coil. Also, incase of placing the wires in the space, the wires can be prevented fromslipping out from the space.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1A is the perspective view of the entire lens driving deviceaccording to one embodiment of the present invention.

FIG. 1B is the perspective view showing the interior of entire lensdriving device wherein the case shown in FIG. 1A is removed.

FIG. 1C is the perspective view of the entire lens driving devicewithout the case as shown in FIG. 1B but looking from the differentangle.

FIG. 1D is the partial enlarged schematic view showing the dampermaterial filled between the damper table and the rear plane of the flameshown in FIG. 1C.

FIG. 2 is the exploded view of the lens driving device wherein the caseshown in FIG. 1A is removed.

FIG. 3A is the perspective view of the lens holder shown in FIG. 2.

FIG. 3B is the perspective view of the lens holder shown in FIG. 3Alooking from the different angle.

FIG. 4A is the perspective view of the flame shown in FIG. 2.

FIG. 4B is the perspective view of the flame shown in FIG. 4A lookingfrom the different angle.

FIG. 4C is the perspective view wherein the flame and the lens holdershown in FIG. 2 are joined.

FIG. 4D is the partial enlarged figure of the essential part of theflame and the lens holder shown in FIG. 4C.

FIG. 4E is the partial enlarged figure of the essential part of only theflame shown in FIG. 4C.

FIG. 4F is the partial enlarged figure of the essential part of only thelens holder shown in FIG. 4C.

FIG. 5A is the top view of arranging the circuit substrate and thedriving coil on the base part shown in FIG. 2, FIG. 5B is the top viewof the first driving coil shown in FIG. 5A, and FIG. 5C is the top viewof the second driving coil shown in FIG. 5A.

FIG. 6A is the perspective view of the partial assembly figure whereinthe circuit substrate and the driving coil are placed on the base partshown in FIG. 5A.

FIG. 6B is the enlarged top view of FIG. 5A, and it shows the relationbetween the lens and the opening part.

FIG. 7 is the cross section view along VII-VII line shown in FIG. 6B,and it is the cross section view wherein the flame and the lens holderare assembled on the upper part along Z axis direction of the partialassembly

FIG. 8 is the enlarged cross section view wherein part of FIG. 7 isenlarged.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, the present invention will be described based on theembodiments shown in the figures.

First Embodiment

As shown in FIG. 1A, the lens driving device 2 according to oneembodiment of the present invention comprises the fixing part 4, and themovable part 3 capable of moving against the fixing part 4. The fixingpart 4 comprises the case 11 which covers the movable part 3 from thefront side (from Z axis positive direction side), and the base part 10covering the movable part 3 from the rear side (from Z axis negativedirection side). The movable part 3 is placed at the inside of the case11, and comprises the lens holder 40 holding the lens, and the flame 60holding the lens holder 40 in a movable manner in the optical axisdirection. At the inner peripheral plane 48 of the lens holder 40, thelens is installed however this is not shown in FIG. 1A.

The lens driving device 2 is used together with, for example, with theimage sensor which is not shown in the figures. The image sensor isplaced at the rear side (Z axis negative direction side) of the lensholder 40, and the light emitted from the lens which is held by the lensdriving device is photoelectrically converted, thereby the image isgenerated. The placing method of the image sensor is not particularlylimited, and it may be directly fixed against the base part 10 of thelens driving device 2, or it may be connected to the lens driving device2 via other members.

The base part 10 and the case 11 are joined at the rear part open end ofthe Z axis direction of the case 11. At the inside of the case 11, asshown in FIG. 1B and FIG. 2, the circuit substrate 20 constituted by FPCor so, the blur correction coil 30 as the driving coil, the lens holder40, the magnet 80 as the driving magnet, and the flame 60 or so areplaced towards the front side along the Z axis direction of the basepart 10. The lens holder 40 and the flame 60 constitute the movable partagainst the fixing part 4.

The circuit substrate 20 and the blur correction coil 30 are a part ofthe fixing part 4; and the common magnet 80 and the flame 60 are part ofthe movable part 3. The movable part 3 includes the front side spring90, the magnetic board 61, focusing coil 46 and the rear side spring 50or so other than the lens holder 40, the magnet 80 and the flame 60.

At the center part of the circuit substrate 20, the substrate openingpart 22 is formed which penetrates through the front and the backplanes. To the substrate opening part 22, the cylinder shape projectionpart 14 formed at the center of the base board main body 10 a of thebase part 10 will be inserted. The cylinder shape projection part isformed along the periphery of the base opening part 12, and it projectsout towards the front side which is the direction parallel to theoptical direction and towards the movable part 3 from the fixing part 4.At the surface (the front plane) of the circuit substrate 20, the blurcorrection coil 30 is provided along the substrate opening part 22. Notethat, the circuit substrate 20 is formed as one body with the base part10.

As it will be described in below, the blur correction coil 30 comprisesa pair of first driving coils 30 a constituting the first driving axis,and a pair of the second driving coils 30 b constituting the seconddriving axis which crosses roughly perpendicularly with the firstdriving axis. These driving coils 30 a and 30 b are fixed to the surfaceof the circuit substrate 20 by an adhesive agent or so.

The circuit substrate 20 included in the fixing part 4 has a rectangularshape as a whole, and the connector part 23 for connecting with theouter circuit is formed at one sides of the rectangular shape. Theconnector part 23 is placed at the side plane of the lens driving device2 as shown in FIG. 1A. Note that, in all of the figures, the directionparallel to the optical axis of the lens 100 (see FIG. 7) fixed at theinner peripheral plane of the lens holder 40 is defined as Z axis, andthe directions perpendicular to the optical axis are defined as X axisdirection and Y axis direction.

Note that, X axis, Y axis and Z axis are perpendicular to each other. Inthe present embodiment, X axis matches the first driving axis, and Yaxis matches the second driving axis. Also, the front plane or the frontside along Z axis in FIG. 2 and FIG. 7 refers to upward direction, andrefers to the image object side with respect to the lens. Also, the rearplane and the rear side along Z axis in FIG. 2 and FIG. 7 refers to thedownward direction, and refers to the image sensor side with respect tothe lens.

As shown in FIG. 2, the base part 10 comprises the base board main body10 a comprising the coil mounting plane 10 aa, and the wire rear endinstallation corners 10 b which is installed at each four corners of thebase board main body 10 a. At the front side of the coil mounting plane10 aa, the blur correction coil 30 is provided via the circuit substrate20. For each wire rear end installation corners 10 b, the rear end ofthe single suspension wire 16 is installed. The suspension wire 16extends towards the front side of Z axis (the upward direction of FIG.2) by penetrating through the four corners of the circuit substrate 20.

At the front plane 42 of the lens holder 40 shown in FIG. 2, the holderinstallation parts 93 a to 93 d of the front side spring 90 areinstalled and fixed. At a part of the outer circumference plane 47 ofthe lens holder 40 along the circumferential direction, the sensor part41 is installed. The sensor part 41 is constituted by hall IC part or sowhich detects, for example, the relative movement of the hall element(hall magnet), and detects the relative position in Z axis direction ofthe lens holder 40 with respect to the flame 60. At the inner plane ofthe flame 60 corresponding to the sensor part 41, the hall magnet isprovided which is omitted in the figures.

The front side spring 90 is constituted by four divisional plate springs90 a to 90 d which are separated and insulated against each other. Eachdivisional plate springs 90 a to 90 d comprises wire installation parts92 a to 92 d having corner shape to which the front end of thesuspension wire 16 is installed. The suspension wire 16 and thedivisional plate springs 90 a to 90 d are constituted by the conductivematerial such as metals, and these can be electrically connected.

The suspension wire 16 as the supporting part connects the front sidespring 90 of the movable part 3, and the base part 10 of the fixing part4. The suspension wire 16 can deflect resiliently along the drivingplane which includes X axis and Y axis. Thereby, the suspension wire 16connects the movable part 3 to the fixing part 4 in manner allowing arelative movement, and the movable part 3 is supported by the fixingpart 4.

Note that, in case an excessive force is applied to the suspension wire16, it is possible to deform resiliently along Z axis direction; howeverin the usual lens driving function, the suspension wire 16 freelydeflect resiliently along the driving plane which includes X axis and Yaxis. In order for the front end of the suspension wire 16 to be easilyconnected to each wire installation parts 92 a to 92 d of eachdivisional plate springs 90 a to 90 d, as shown in FIG. 4A, notch parts62 are provided respectively to four corner parts of the flame 60.

Each divisional plate springs 90 a to 90 d comprises flame installationparts 94 a to 94 d respectively which are continuous with the respectivewire installation parts 92 a to 92 b of the corner shape. Each flameinstallation parts 94 a to 94 d is for example installed and fixed atfour corner parts positioned at the front plane 64 of the flame 60having the square ring shape as shown in FIG. 4A. The flame 60 itself isconstituted by the insulation material such as plastic or so.

At the front plane positioned at the corner part of the flame 60,preferably plurality of installation projection parts 65 are formed.Each installation projection parts 65 fits to the fitting hole formed atthe flame installation parts 94 a to 94 d of the divisional platesprings 90 a to 90 d as shown in FIG. 1B and FIG. 2, and it is fixed bydetermining the position of the divisional plate springs 90 a to 90 d onthe flame 60.

At flame installation parts 94 a to 94 d of each divisional platesprings 90 a to 90 d, the holder installation parts 93 a to 93 d areformed respectively via the meandering parts 95 a to 95 d. At the holderinstallation parts 93 a to 93 d, the fitting holes are respectivelyformed. The fitting holes fit to the installation projection parts 43 ato 43 d which are formed roughly equally along the circumferentialdirection of the front plane 42 of the lens holder 40 as shown in FIG.3A. The divisional board springs 90 a to 90 d are fixed by adhesion orso to the front plane 42 of the lens holder 40 while the installationprojection parts 43 a to 43 d of the lens holder 40 are inserted to thefitting hole.

That is, as the meandering parts 95 a to 95 d deforms resiliently, thefront side spring 90 holds the lens holder 40 in a movable manner alongZ axis direction which is the optical axis direction with respect to theflame 60, due to the holder installation parts 93 a to 93 d formed atthe inner peripheral edge of the front side spring 90.

Further, each divisional plate springs 90 a to 90 d of the front sidespring 90 are connected to different suspension wire 16 respectively,and also connects to the wire pattern formed on the front plane of thelens holder 40. Therefore, the driving current is supplied to thefocusing coil 46 held by the lens holder via the suspension wire 16 andthe front side spring 90, and also the detected signal by the sensorpart 41 is transmitted to the circuit substrate 20. Each suspension wire16 can be electrically connected to the wire pattern of the circuitsubstrate 20.

As shown in FIG. 3B, at the rear plane 45 of the lens holder 40, theplate spring installation parts 44 a and 44 b having the arc shape areformed. Also, at the back side of the outer circumference plane 47 ofthe lens holder 40, the step part 49 is formed. At the step part 49, thesquare ring shape focusing coil 46 shown in FIG. 2 is fixed.

As shown in FIG. 2, the rear side spring 50 is constituted by a pair ofthe divisional plate springs 50 a and 50 b. For each divisional platesprings 50 a and 50 b, the holder installation parts 54 a and 54 bhaving the arc shape are formed at each of the inner circumference partsthereof. Each holder installation parts 54 a and 54 b are fixed to theplate spring installation parts 44 a and 44 b as shown in FIG. 3B. Asfor the means of fixing the rear side spring 50 to the plate springinstallation parts 44 a and 44 b, it is not particularly limited, andfor example the fixing by fitting or by adhesive agent or so may bementioned.

As shown in FIG. 2, the meandering parts 55 a to 55 b are formedcontinuously with the both end parts of the holder installation parts 54a and 54 b; and at the outer circumference side of the meandering parts55 a and 55 b, the flame installation parts 52 a and 52 b are formedcontinuously. Each flame installation parts 52 a and 52 b are fixed tothe corner part rear plane 68 of the flame 60 by fitting.

That is, similar to the front side spring 90, because the meanderingparts 55 a to 55 d deforms resiliently, in the rear side spring 50, thelens holder 40 is held, in a movable manner along Z axis direction whichis the optical axis direction with respect to the flame 60, by theholder installation parts 54 a to 54 d formed at the inner circumferenceend. Note that, the rear side spring 50 does not necessarily need theelectrical conductive path way function, which is different from thefront side spring 90.

As shown in FIG. 4A and FIG. 4B, at the back side in Z axis direction ofthe square ring shape flame 60, the magnet installation depression parts66 are formed along the four sides of the square. At the magnetinstallation depression parts 66, as shown in FIG. 2 and FIG. 7, themagnet 80 is fixed via the magnetic board 61.

As shown in FIG. 7, the flame 60 is held to the base part 10 by thesuspension wire 16 so that the space is formed between the rear plane ofthe magnet 80 and the front plane of the blur correction coil 30. Theflame 60 is held in a movable manner along the driving plane whichincludes X axis and Y axis with respect to the base part 10.

At the flame 60, the lens holder 40 is held in a movable manner along Zaxis direction via the front side spring 90 and the rear side spring 50as shown in FIG. 2, therefore together with the flame 60, the lensholder 40 also moves along the driving plane which includes X axis and Yaxis with respect to the base part 10.

By allowing the driving current to flow to the blur correction coil 30,due to the combined effect (VCM effect) of the coil 30 and the magnet80, the force along the perpendicular direction with the optical axisacts on the magnet 80. Therefore, together with the lens holder 40, theflame 60 can move along the driving plane which includes X axis and Yaxis, with respect to the base part 10. By moving the lens 100 with thelens holder 40 along the driving plane, the blur correction can becarried out.

Also, since the space is formed between the inner circumference plane ofthe magnet 80 and the outer circumference plane of the focusing coil 46,the lens holder 40 is held by the flame 60 via the springs 90 and 50(see FIG. 2). By allowing the driving current to flow to the focusingcoil 46, the combined effect (VCM effect) of the coil 30 and the magnet80, the force along the optical axis direction acts on the coil 46.Therefore, the lens 100 with the lens holder 40 can move back and forthalong the optical axis direction with respect to the flame 60. By movingthe lens 100 with the lens holder 40 along the optical axis directionwith respect to the flame 60, the autofocus (AF) can be carried out.

In the present embodiment, the magnet 80 functions both as the AFcontrol magnet and the blur correction control magnet, thereby thenumber of the parts can be reduced, and hence AF control and blurcorrection control can be carried out by a simple constitution. Further,it can contribute to achieve a compact lens driving device.

Note that, the lens 100 may be constituted by plurality of the lensgroups; however in order to make the explanation simple, the embodimentof using one lens will be used for describing the present embodiment.

As shown in FIG. 6A and FIG. 6B, the blur correction coil 30 comprises apair of first driving coils 30 a and 30 a which are opposing againsteach other by placing the opening part 12 in between along X axisdirection, and a pair of the second driving coils 30 b and 30 b whichare opposing against each other by placing the opening part 12 inbetween along Y axis direction. These driving coils 30 a and 30 b areplaced, as a whole, on the front plane of the circuit substrate 20 ofthe square board shape, and are placed parallel along each sides of thecircuit substrate 20 so as to surround the cylinder shape projectionpart 14.

The position of placement along Y axis direction of the first drivingcoils 30 a and 30 a opposing against each other along X axis directionsis slightly off positioned; and the position of placement along X axisdirection of the second driving coils 30 b and 30 b opposing againsteach other along Y axis directions is slightly off positioned as well.The driving coils 30 a and 30 b are slightly off positioned along thecircumference direction as such because this allows the position sensors18 a and 18 b and the dumper 24 to be mounted easily on the four cornersof the circuit substrate 20, and also to easily form the through hole orso for the suspension wire 16.

The position sensor 18 a is, for example, constituted by the hallsensor. The position sensor 18 a and one of the first driving coils 30 atogether face against the rear plane of one of the first driving magnet80 a of the magnet 80 shown in FIG. 2, while taking predetermined spacewith the first driving magnet 80 a; thereby the moving position along Xaxis direction of the first driving magnet 80 a can be detected. Also,the position sensor 18 b is, for example, constituted by the hallsensor. The position sensor 18 b and one of the second driving coils 30b together face against the rear plane of one of the second drivingmagnet 80 b of the magnet 80 shown in FIG. 2 while taking predeterminedspace with the second driving magnet 80 b; thereby the moving positionalong Y axis direction of the first driving magnet 80 b can be detected.These sensors 18 a and 18 b are electrically connected to the wirepattern of the circuit substrate 20.

In the present embodiment, the first driving coil 30 a and the firstdriving magnet 80 a are placed along Z axis while taking a predeterminedspace therebetween to constitute the first driving part (the first VCM)for the blur correction. The second driving coil 30 b and the seconddriving magnet 80 b are placed along Z axis while taking a predeterminedspace therebetween to constitute the second driving part (the secondVCM) for the blur correction. The first driving axis of the firstdriving part is X axis, and the second driving axis of the seconddriving part is Y axis.

The damper tables 24 shown in FIG. 6A and FIG. 6B are respectively fixedto four corners of the circuit substrate 20 by means of the adhesiveagent or by reflow or so. As shown in FIG. 1C and FIG. 1D, between thefront plane of the damper table 24 and the corner part rear plane 68 orthe rear plane projection part 69 of the flame 60, the space having thespace width W1 is formed; and the first damper material 70 a of gel formis present in this space so as to adhere to the both. The space width W1is made wider than the space width W0 which is the space between themagnet 80 and the blur correction coil 30, and specifically the spacewidth W1 is preferably 0.1 to 0.4 mm or so.

The first damper material 70 a is for example constituted by a vibrationabsorbing material such as a soft gel material or a soft adhesive agentor so. The first damper material 70 a functions as the damper when theflame 60 moves long the driving plane which includes X axis and Y axiswith respect to the base 10 and the circuit substrate 20, and thus thesuppression of the vibration can be expected.

In the present embodiment, the first damper material 70 a is not placedbetween the magnet 80 and the coil 30, but it is placed between thedamper table 24 and the corner part rear plane 68 of the flame 60, orbetween the damper table 24 and rear plane projection part 69 of theflame 60. Furthermore, the space width W1 is wider than the space widthW0. Therefore, in the present embodiment, even if the impact is appliedsuch as dropping the portable devices or so including the lens drivingdevice 2, the magnet 80 and the coil 30 will collide thereby the stopperfunction comes into effect. Therefore, the first damper material 70 acan be held between the damper table 24 and the corner part rear plane68 of the flame 60, or between the damper table 24 and rear planeprojection part 69 of the flame 60; hence the damper characteristic canbe maintained in good condition even after the impact.

Also, in the present embodiment, as shown in FIG. 4A to FIG. 4E, atinner side of each four corner of the flame 60, the inner sideprojection parts 72 are formed which project towards the inside. Asshown in FIG. 4D, the width W2 between the inner side projection part 72and the outer circumference plane 47 of the lens holder 40 is preferably0.1 to 0.3 mm or so. At the space of this width W2, the second dampermaterial 70 b is filled; and in this space, the second damper material70 b adheres to the inner side projection part 72 and to the outercircumference plane 47 of the lens holder 40. The second damper material70 b is constituted by similar material as the first damper material 70,but it does not have to be exactly the same.

As shown in FIG. 4E, at the front plane 73 of the inner side projectionpart 72, the damper depression part 74 is formed. The second dampermaterial 70 b is filled in this damper depression part 74 and in thespace. The second damper material 70 b in the space and the seconddamper material 70 b filled in this damper depression part 74 arecontinuous. The second damper material 70 b in the damper depressionpart 74 functions as the gel reservoir which can provide the dampermaterial to the space, thus even if the impact is applied to the lensdriving device 2, the risk of the second damper material 70 b slippingout of the space is low.

The second damper material 70 b functions as the damper when the lensholder 40 is focus driving along the optical axis direction (Z axisdirection) with respect to the flame 60, thereby the suppression of thevibration can be expected. In the present embodiment, by providing thesecond damper material 70 b near by the four corner parts of the flame60 of the square shape, the damper materials 70 b at the four positionscan be placed at the position furthest from the center axis of the lens,thus the function as the damper can be fully exhibited. Note that, asshown in FIG. 4C, one of the damper materials 70 b at the four positionsmay be provided at the space between the sensor part 41 installed at thepart of the lens holder 40, and the inner circumference plane of theflame 60.

In the present embodiment, as shown in FIG. 6B, at the base part 10B,the opening part 12 is formed wherein a part of the lens 100 is to beinserted in a movable manner along the driving plane which includes thefirst driving axis (X axis) and the second driving axis (Y axis). In thepresent embodiment, the oblique inner diameter Dxy1 and Dxy2 of theopening part 12 along the oblique direction positioned at the middle ofthe first driving axis (X axis) and the second driving axis (Y axis), islarger than the first inner diameter Dx along X axis direction of theopening part 12, and also larger than the second inner diameter Dy alongY axis direction of the opening part 12.

In the present embodiment, the first inner diameter Dx and the secondinner diameter Dy are roughly the same. Also, the oblique inner diameterDxy1 and Dxy2 are roughly the same with respect to each other. Theoblique inner diameter Dxy1 and Dxy2 have the maximum length at near thebisector of the crossing angle between the straight line along the firstinner diameter Dx and the straight line along the second inner diameterDy; and as getting closer to the straight line along the first innerdiameter Dx or the second inner diameter Dy, preferably the obliqueinner diameter Dxy1 and Dxy2 approach the first inner diameter Dx andthe second inner diameter Dy. Note that, the position of the obliqueinner diameter Dxy1 and Dxy2 are not particularly limited, and at anyposition in the middle of the first driving axis (X axis) and the seconddriving axis (Y axis), these only need to be larger than the first innerdiameter Dx and the second inner diameter Dy.

In the present embodiment, the opening part 12 has n-polygonal shape;and the maximum value of the oblique inner diameter Dxy1 and Dxy2 arewithin 45 degrees (½ of the crossing angle of X axis and Y axis)±(360/n)with respect to X axis and Y axis. Note that, the shape of the innercircumference plane of the opening part 12 is not limited to polygonalshape, and it may be a curved shape. In such case, the maximum value ofthe oblique inner diameter Dxy1 and Dxy2 are within 45 degrees (½ of thecrossing angle of X axis and Y axis)±15 degrees with respect to X axisand Y axis.

The inner diameter of the opening part 12 continuously changes orchanges in a stepwise manner from the position where the oblique innerdiameter Dxy1 and Dxy2 take the maximum value, to the first innerdiameter Dx or the second inner diameter Dy. Note that, it may simplydecrease from the maximum value of the oblique inner diameter Dxy1 andDxy2 towards the first inner diameter Dx or the second inner diameterDy; or it may approach towards the first inner diameter Dx or the secondinner diameter Dy while repeating increase and decrease. The maximumvalue of the oblique inner diameter Dxy1 and Dxy2 are preferably 1.02 to1.05 times of the first inner diameter Dx or the second inner diameterDy.

In the lens driving device 2 according to the present embodiment, asshown in FIG. 6B, the oblique inner diameters Dxy1 and Dxy2 of theopening part 12 along the oblique direction positioned at the middle ofX axis and Y axis is larger than the first inner diameter Dx along Xaxis direction of the opening part 12, and also larger than the secondinner diameter Dy along Y axis direction of the opening part 12. Bytaking such constitution, not only in case of moving the lens 100 alongX axis direction or Y axis direction, but also in case of moving alongthe oblique direction in middle thereof, there is no risk of the lens100 to collide against the inner circumference plane of the cylindershape projection part 14 constituting the periphery of the opening part12.

That is, the maximum moving amount of the lens 100 along the obliquedirection is the smaller value of the values obtained by dividing themaximum moving amount along the first and second driving axis directionwith cosine of interior angle (0 to 90°) formed between the driving axisthereof and the oblique direction; and the maximum moving amount of thelens 100 along the oblique direction is larger than the maximum movingamount along the first and the second driving axis direction. However,by making the oblique inner diameter Dxy1 and Dxy2 larger than the firstinner diameter Dx and the second inner diameter Dy, the space betweenthe circular shape lens 100 and the periphery of the opening partbecomes larger along the oblique direction, hence the lens 100 isprevented from colliding into the periphery of the opening part 12.

Further, for the lens driving device 2 according to the presentembodiment, the opening part 12 formed at the base part 10 is not aperfect circle, and has an atypical shape wherein the inner diameterDxy1 and Dxy2 along the oblique direction positioned between X axisdirection and Y axis direction is larger than the inner diameter in Xaxis direction or Y axis direction. Therefore, compared to the openingpart having the perfect circle shape which was determined based on themaximum moving amount towards the oblique direction, the size of thebase part 10 can be made small, thus this contributes to make the devicecompact. Particularly, as shown in FIG. 6B, along the oblique directionwhich crosses with X axis and Y axis, there is still a space left, henceeven if the inner diameter of the opening part 12 is enlarged in suchdirection, there is no need to enlarge the size of the base part 10 andthe circuit substrate 20.

Also, if the size of the base part 10 and the circuit substrate 20 isthe same, compared to the opening part having the perfect circle shapewhich was determined based on the maximum moving amount towards theoblique direction, in the present embodiment, the base part 10 can beenlarged but excluding the opening part 12 along X axis and Y axis.Therefore, the number of windings of the first driving coils 30 a andthe second driving coils 30 b can be increased, hence the driving forceis enhanced, and the accuracy of the blur correction is improved.

Further, in the present invention, the first driving part includes apair of the first driving coils 30 a positioned along X axis directionwhile placing the opening part 12 therebetween; and a pair of the firstdriving coils 30 a are placed parallel along opposing two sides of thebase 10. By taking such constitution, the driving force along X axisdirection is enhanced and the accuracy of the blur correction improves.

Also, the second driving part includes a pair of the second drivingcoils 30 b positioned along Y axis direction while placing the openingpart 12 therebetween; and a pair of the second driving coils 30 b areplaced parallel along opposing two sides of the base 10. By taking suchconstitution, the driving force along Y axis direction is enhanced andthe accuracy of the blur correction improves.

Further, as shown in FIG. 4A, the flame 60 has a square ring shape as awhole; and as shown in FIG. 1, the flame 60 is placed inside of the case11 having the square cylinder shape which is fixed to the base 10, andthe oblique direction roughly matches the direction of the diagonal lineof the square ring shape. By taking such constitution, as shown in FIG.6B, the first driving coils 30 a and the second driving coils 30 b canbe placed efficiently on the base part 10 excluding the opening part 12,hence the size of the base part 10 can be made small, and therefore thedevice 2 can be compact.

Further, in the present embodiment, as shown in FIG. 6B, the cylindershape projection part 14 is formed at the base part 10 along theperiphery of the opening part 12; and the first driving coils 30 a andthe second driving coils 30 b are placed around the cylinder shapeprojection part 14. By taking such constitution, the first driving coils30 a and the second driving coils 30 b placed around the cylinder shapeprojection part 14 can be effectively prevented from colliding againstthe lens 100.

Also, by having the cylinder shape projection part 14, the dusts or sopresent on the surface of the base part 10 and the circuit substrate 20becomes difficult to enter to the inside of the opening part 12. Thelens 100 is inserted at the inside of the opening part 12, and the imagesensor or so is placed at the rear position along the optical axisdirection of the lens 100. If the dusts or so adheres to the imagesensor, the quality of the images to be taken may decline, thus thedusts or so preferably does not enter inside the opening part 12.

Further, as shown in FIG. 5A to FIG. 5C, by having the cylinder shapeprojection part 14, the wires 32 a which connects a pair of the firstdriving coils 30 a, and the wires 32 b which connects a pair of thesecond driving coils 30 b can be easily placed along the outercircumference plane of the cylinder shape projection part 14. Also, byefficiently using the corner space between the cylinder shape projectionpart 14 and each driving coils 30 a and 30 b, the lead wires 34 a and 34b of the driving coils 30 a and 30 b respectively can be easilyconnected to the circuit pattern of the circuit substrate 20.

Second Embodiment

The lens driving device 2 according to the second embodiment of thepresent invention comprises the same constitution and exhibits the sameeffect as the lens driving device 2 of the first embodiment, except forshown in below. Hereinafter, the parts which differ from the firstembodiment will be mainly discussed, although some parts may overlap.

In the present embodiment, the opening part 12 shown in FIG. 6B may be ageneral opening part, and the oblique inner diameter Dxy1 and Dxy2 doesnot necessarily have to be larger than the first inner diameter Dx alongX axis direction of the opening part 12, and also these do notnecessarily have to be larger than the first inner diameter Dy along Yaxis direction of the opening part 12. Also, in the present embodiment,a part of the lens 100 shown in FIG. 7 does not necessarily have to bein the opening part 12.

In the present embodiment, as shown in FIG. 6B, at the base part 10, thecylinder shape projection part 14 is formed along the periphery of thebase opening part 12, similar to the aforementioned embodiment. As shownin FIG. 8 which is the enlarged view of FIG. 7, the coil mounting plane10 aa is provided at the outer circumference side of the cylinder shapeprojection part 14 wherein the coil mounting plane 10 aa is the planewhere the blur correction coil 30 is provided. The coil mounting plane10 aa is formed on the plane of the base part 10 facing the front side;and the first driving coils 30 a and the second driving coils 30 b areprovided at the coil mounting plane 10 aa via the circuit substrate 20.

The cylinder shape projection part 14 projects out towards the frontside from the coil mounting plane 10 aa; and the projection end 14 awhich is the end part in the front side of the cylinder shape projectionpart 14 is positioned at further front than the coil mounting plane 10aa of the base part 10. Also, the coil front end 30 c which is the endpart in the front side of the blur correction coil 30 (the first drivingcoil 30 a in FIG. 8) placed on the coil mounting plane 10 aa ispositioned at further front than the projection end of the cylindershape projection part 14.

The lens driving device 2 comprising such cylinder shape projection part14 can stop the particles by the cylinder shape projection part 14 evenin case the particles are generated in the lens driving device 2.Therefore, the lens driving device 2 can prevent the particles generatedin the lens driving device 2 from flowing into the image sensor sidewhich is at the rear side via the base opening part 12. If the particlesadhere on the light receiving plane of the image sensor, the quality ofthe images generated by the image sensor may be deteriorated; or in casethe particles are conductive material, this may damage the image sensor,however such problems can be prevented by the cylinder shape projectionpart 14.

Also, since the projection end 14 a of the cylinder shape projectionpart 14 is positioned further rear side than the coil front end 30 c ofthe blur correction coil 30, even in case the movable part 3 and thefixing part 4 contacts against each other due to the impact from theoutside, the coil front end 30 c receives the impact by contacting withthe magnet 80, thereby the cylinder shape projection part 14 can beprevented from directly contacting with the movable part 3. Therefore,even if the movable part 3 and the fixing part 4 collides against eachother due to the impact from the outside, the lens driving device 2 canprevent the particles generated by the impact from flowing into theimage sensor side via the base opening part 12, because the position ofthe collision is at further outer circumference side than the cylindershape projection part 14.

Furthermore, in the lens driving device 2, as shown in FIG. 8, a space15 with a predetermined width is formed between the outer circumferenceside plane 14 b of the cylinder shape projection part 14 and the blurcorrection coil 30. By having such space 15, even if the particles movesalong the coil front end 30 c of the blur correction coil 30 towards thebase opening part 12, these particles will be trapped in the space 15.Therefore, the lens driving device 2 formed with such space 15 caneffectively prevent the flowing of the particles into the base openingpart 12. Note that, as shown in FIG. 7, if the diameter of the lens 100is made large, the opening area of the base opening part 12 also becomeslarge, hence the particles tends to easily flow into the image sensorside, however the lens driving device 2 can prevent such particles fromflowing in, hence it is particularly suitable as the lens driving deviceholding the lens 100 with large diameter.

As shown in FIG. 6B, in the lens driving device 2, the total area of thecoil front end 30 c which is the sum of four blur correction coils 30 ismade larger than the area of the projection end 14 a in order to securethe driving force for the blur correction. The lens driving device 2 isstructured to receive the impact of the collision between the movablepart 3 and the fixing part 4 by the coil front end 30 c having largerarea than the projection end 14 a, hence the particles are preventedfrom being generated because a strong external force acts to a narrowrange. Also, the damper material 70 a shown in FIG. 1C functions as thebuffer material to reduce the impact generated during the collisionbetween the movable part 3 and the fixing part 4, thereby suppress theparticles from being generated in the lens driving device 2.

Furthermore, as shown in FIG. 5A to FIG. 5C, in the lens driving device2, the wire 32 a as the wire part for connecting a pair of the firstdriving coils 30 a, and the wire 32 b as the wire part for connecting apair of the second driving coils 30 b are placed in the space 15 formedbetween the outer circumference side plane of the cylinder shapeprojection part 14 and the blur correction coil 30. By placing the wires32 a and 32 b which connects to the blur connection coil 30 in the space15, the wire distance of the blur correction coil 30 can be shortened,and also the space for placing other members in the base part 10 can beenlarged. Also, by efficiently using the corner space between thecylinder shape projection part 14 and each driving coils 30 a and 30 b,the lead wires 34 a and 34 b of the driving coils 30 a and 30 brespectively can be easily connected to the circuit pattern of thecircuit substrate 20. Note that, in the figures, the wires 32 a and 32 bare omitted, except for FIG. 5A to FIG. 5C.

As shown in FIG. 5A, the outer circumference shape of the cylinder shapeprojection part 14 is polygonal shape as similar to the base openingpart 12; and the outer circumference side plane 14 b of the cylindershape projection part 14 comprises the projection part flat plane parts14 ba which are the flat plane part extending in parallel to the flatplane including the optical axis. The projection part flat plane parts14 ba extending in parallel to the flat plane including the optical axisare formed at four places of the outer circumference side plane 14 b ofthe cylinder shape projection part 14. Each of the projection part flatplane parts 14 ba faces against each other by placing the space 15 inbetween with respect to the coil flat plane part 30 d, which is part ofthe outer circumference side plane of the blur correction coil 30 and isthe flat plane part extending in parallel to the flat plane includingthe optical axis.

Since such projection part flat plane parts 14 ba are formed, the lensdriving device 2 can easily place the wires 32 a and 32 b along theouter circumference side plane 14 b of the cylinder shape projectionpart 14; and also the wires 32 a and 32 b can be prevented from slippingout from the space 15 due to the impact or so. Further, by forming thespace 15 having certain width and predetermined length along X axis andY axis directions, the particles can be easily trapped in the space 15;thereby the particles can be prevented more effectively from flowinginto the case opening part 12.

Note that, the present invention is not limited to the aforementionedembodiments, and can be variously modified. For example, in the abovementioned embodiment, the driving force of the blur correction coil 30is made larger by fixing each of the driving coils 30 a and 30 b to thesurface of the circuit substrate 20; however in case there is no need toincrease the driving force, the circuit substrate embedded with the coilmay be used.

Also, in the above mentioned embodiment, the first driving axis and thesecond driving axis are placed in parallel to each side of square boardshape base part 10 and the circuit substrate 20; however these may notbe limited thereto. For example, the first driving coil 30 a and thesecond driving coil 30 b may be placed so that the first driving axisand the second driving axis are positioned on the diagonal line of thesquare board shape base part 10 and the circuit substrate 20.

Further, in the above mentioned embodiments, single magnet 80 functionsas both the blur correction magnet and the autofocus magnet; howeverseparate magnets may be prepared and installed.

Furthermore, in the above mentioned embodiments, the lens driving device2 comprises two mechanism which are the autofocus mechanism and the blurcorrection mechanism; however the lens driving device of the presentinvention may have at least blur correction mechanism.

Also, in the above mentioned embodiment, the crossing angle between thefirst driving axis and the second driving axis was 90 degrees; however,for the present invention, these crossing angles may be other than 90degrees. Also, these driving axes may cross in the angle other thanperpendicular angles with respect to the optical axis.

In the above mentioned embodiments, four suspension wires 16 are used asthe means to hold the flame 60 as the movable part moving freely alongthe driving plane (including X axis and Y axis) with respect to the basepart 10 as the fixing part; however the number of the suspension wiresis not limited to four, and plural numbers may be used.

NUMERICAL REFERENCES

-   2 . . . Lens driving device-   3 . . . Movable part-   4 . . . Fixing part-   10 . . . Base part-   11 . . . Case-   12 . . . Base opening part-   14 . . . Cylinder shape projection part-   16 . . . Suspension wire-   18 a, 18 b . . . Position sensor-   20 . . . Circuit substrate-   22 . . . Substrate opening part-   23 . . . Connector part-   24 . . . Damper table-   30 . . . Blur correction coil-   30 a . . . First driving coil-   30 b . . . Second driving coil-   30 c . . . Coil front end-   30 d . . . Coil flat plane portion-   40 . . . Lens holder-   41 . . . Sensor part-   42 . . . Front plane-   43 a to 43 d . . . Installation projection parts-   44 a, 44 b . . . Plate spring installation parts-   45 . . . Rear plane-   46 . . . Focus coil-   47 . . . Outer circumference plane-   48 . . . Inner circumference plane-   49 . . . Step part-   50 . . . Rear side spring-   50 a, 50 b . . . Divisional plate springs-   52 a, 52 b . . . Flame installation parts-   54 a, 54 b . . . Holder installation parts-   55 a, 55 b . . . Meandering parts-   60 . . . Flame-   61 . . . Magnetic board-   62 . . . Notch part-   64 . . . Front plane-   65 . . . Installation projection part-   66 . . . Magnet installation depression part-   68 . . . Corner part rear plane-   69 . . . Rear plane projection part-   70 a . . . First damper material-   70 b . . . Second damper material-   72 . . . Inner side projection part-   73 . . . Front plane-   74 . . . Damper depression part-   80 . . . Magnet-   80 a . . . First driving magnet-   80 b . . . Second driving magnet-   90 . . . Front side spring-   90 a to 90 d . . . Divisional plate spring-   92 a to 92 d . . . Wire installation parts-   93 a to 93 d . . . Holder installation parts-   94 a to 94 d . . . Flame installation parts-   95 a to 95 d . . . Meandering parts-   100 . . . Lens

1. A lens driving device comprising a first driving part allowing a lenspart including at least one lens to relatively move against a base partalong a first driving axis crossing with an optical axis of said lens, asecond driving part allowing said lens part to relatively move againstsaid base along a second driving axis crossing with said optical axis ofthe lens and with said first driving axis, wherein an opening part isformed at said base part to which a part of said lens is inserted in amovable manner along a driving plane including said first driving axisand said second driving axis, and an oblique internal diameter of saidopening part along an oblique direction positioned in the middle of saidfirst driving axis and said second driving axis is larger than a firstinternal diameter of said opening part along a direction of said firstdriving axis, and also larger than a second internal diameter of saidopening part along a direction of said second driving axis.
 2. The lensdriving device as set forth in claim 1 wherein said first driving partincludes a pair of first driving coils positioned at both sides alongsaid first driving axis direction while placing said opening parttherebetween, and a pair of said first driving coils are placed parallelalong opposing two sides of said base part.
 3. The lens driving deviceas set forth in claim 1, wherein said second driving part includes apair of second driving coils positioned at both sides along said seconddriving axis while placing said opening part therebetween, and a pair ofsaid second driving coils are placed parallel along opposing two sidesof said base part.
 4. The lens driving device as set forth in claim 1,wherein said lens part is held at a flame in a movable manner in theoptical axis direction, and said flame is held in a movable manner alongsaid driving plane against said base part using plurality of suspensionwires.
 5. The lens driving device as set forth in claim 1, wherein saidflame has a square ring shape as a whole and placed inside a case ofsquare cylinder shape fixed to said base, and said oblique directionroughly matches to a diagonal line direction of said square ring shape.6. The lens driving device as set forth in claim 1, wherein a cylindershape projection part is formed at said base part along a periphery ofthe opening part, and at least part of said first driving part and saidsecond driving part are placed around said cylinder shape projectionpart.
 7. A lens driving device comprising, a movable part having a lensholder holding a lens and a driving magnet for driving said lens inoptical axis perpendicular direction, a fixing part having a drivingcoil placed to face against said driving magnet to drive said lens insaid optical axis perpendicular direction, and a base part formed with abase opening part to allow an incident light on said lens to passthrough and the base part is also provided with said driving coil, and asupporting part connecting said movable part to said fixing part inrelative movable manner, and supporting said movable part to said fixingpart, wherein a cylinder projection part which projects out along theoptical axis direction of said lens towards said movable part is formedalong a peripheral of said base opening part at said base part, aprojection end of said cylinder shape projection part is positioned atfront side along the optical axis direction of said lens than a coilmounting plane where said driving coil is mounted in said base part, anda coil front end of said driving coil is positioned at front side alongsaid optical axis direction than said projection end.
 8. The lensdriving device as set forth in claim 7, wherein a predetermined space isformed between an outer peripheral side plane of said cylinder shapeprojection part and said driving coil.
 9. The lens driving device as setforth in claim 8 wherein a wire connecting to said driving coil isplaced in said space.
 10. The lens driving device as set forth in claim8, wherein said outer peripheral side plane of said cylinder projectionpart comprises a projection part flat plane part extending parallel to aflat plane including said optical axis, and said projection part flatplane part faces against, by placing the space in between, a coil flatplane part which is part of the outer circumference side plane of saiddriving coil and extending parallel to the flat plane including saidoptical axis.